Studies in Valine Biosynthesis VII. An Enzymatic Clue in Penicillium chrysogenum and Other Organisms.

Abstract
Conclusions A dihydroxyacid dehydratase has been detected in extracts of 2 Actino-mycetes, 3 Ascomycetes, a Basidiomycete and 3 Fungi Imperfecti, and provides a clue for the specific pathway of valine and isoleucine biosynthesis in the organisms studied. Some methods of extraction of the dehydratase were compared. This enzymatic evidence complements earlier isotopic studies on the route of formation of the valine moiety in the ring of penicillin and cephalosporin C.